Daimler trademarked three "73" model names in Europe in late 2017 - G 73, GLS 73, and S 73. The automaker did the same in Canada in early 2018. The last time Mercedes used the designation was on the R129 SL 73 produced from 1999 to 2001, powered by a 7.3-liter V12 with 518 hp and 553 pound-feet of torque. The coming incarnation of the 73 powertrain has been predicted for the next SL, which AMG is developing, and mooted as a possible engine for a resurrection of the Mercedes-McLaren SLR.
All of these theoretical AMG GT 73 figures, should they come to production, will loom over the only real competition, the Panamera Turbo S E-Hybrid. The Porsche has 677 combined horses and 626 lb-ft, gets to 60 mph in 3.3 seconds, and has an electric range of up to 20 miles. The AMG GT 63 S is already faster than the Porsche in the stoplight sprint, and the 73 version could break the three-second barrier. As well, Autocar's shooters said they heard the hybrid AMG GT leave the scene on electric power, and the magazine predicts an all-EV range of up to 31 miles.